Improvement in saw-swage



@sind (tithe.

Letters Patent No. 92,076, dated June 29, 1869.

IMPROVEMENT IN SAW-SWAGE.

The Schedule referred to in these Letters Patent and making part 0f the Same- To all whom it may concern.:

Be it known that I, J OHN MCDONALD, of Portville, in the county of Cattaraugus, and State of New York, have invented a certain new and useful Improvement in Swages for Spreading the Under Side of the Teeth at the Point, for Sharpening Mill, Circular', and other Saws; and the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings, making a part of this specitication, in which- Figure 1 represents the apparatus as applied to a tooth on the section of a large circular saw.

Figure 2 shows two views of the stock-swage and slide-punch, with the spring inside, as constructed complete for operation.

The object ot' my invention is to spread the points of saw-teeth on their under side uniformly and truly, and make them of a sucient width to avoid the necessity of any other setting or filing on the under side.

My invention consists iu the construction of the stock, with the sliding punch, whose bevel face, in combination with the gauge-tace of' the stock, gives the form and spreads the 4point of the tooth on its under side, and sets and sha1-pens the saw at the saine time.

` That others may be enabled to make and use my invention, I will describe it more fully, referring to the drawings, and to the letters marked thereon.

I make the stock A of castor wrought-iron, or steel, it being provided with an offset, e, to form the face of the portion that rests on the top of the sawtooth B.

The sliding punch C is fitted into a groove, b, in the stock A, the bottom of which is on a direct line with the face (t in the offset, so that the punch C tits ciosely and slides on the face, and is held tirml y against it by a strong metal socket, D, through which the punch O slides, and is provided with a helical spring, al., placed in recesses c, in both the stock and punch, to hold the punch C against the shoulder foi' the offset a..

The punch G has the corner taken oii` at any desired angle to form a bevelled face, l1, where its operating portion rests against the gauge-tace (t in the ofiset, which bevel or angle gives the precise form or Shape to the point 'i of' thesaw-tooth B, and swages or spreads ont both ways the point of the tooth on the under side, where the concussion of the blow is brought to bear by the action of a hammer on the other end oi' the punch E.

rBhe point yi ot' the tooth, coming in the joint j, meets with 11o obstacle, and is thus brought to a tine, sha-rp edge. At the same time the tooth is being spread out sideways sntiicieutly to make it cut clear, so that no other setting to the saw is required, and no tiling on the under side of the teeth, and much less on the top, as the swag-ing not only gives the teeth a uniform, nice, sharp cuttingedge,bi1t it also hardens and .tempers them, so that they 'will 'retain their cuttingedge much longer than when the points are left from the. tile.

What I claim as my invention, and desire to secure by Letters Patent, is

The sliding punch C, whose bevel-face It is in contact with the gauge-face c, in combination with spring d, substantially as and for the purposcsset forth.

In .testimony whereof, l hereunto subscribe my name, in the presence of` JOHN MCDONALD.

iliitnesses;

W. H. S'rENsoN, I. F. GLEASON. 

